On a Mac with Apple silicon
This works for USB drives including the NinjaStik For 2018 to 2020 Macs with the Secure Boot T2 Chip, see the 2020 Macbook Pro Boot from USB instructions. A “startup disk” is a volume or partition of a drive that contains a bootable operating system. Select the “Install macOS Catalina” (with left/right arrow keys) and hit the “return/enter” key to boot from the USB flash drive. It may take 5-10 minutes to load the installer from the USB flash drive. Sometimes the progress bar may appear to be frozen or the screen will go black for a minute or two. Step 3: convert ISO into bootable DMG. WARNING: this is an important step, without it your USB stick won’t boot. So I have this DVD ISO of the CentOS 7.4, let’s convert it before burning onto the USB stick. $ hdiutil convert -format UDRW -o centos./CentOS-7-x8664-DVD-1708.iso. Reading Master Boot Record (MBR: 0).
Turn on your Mac with Apple silicon and continue to press and hold the power button until you see the startup options window. From there you can start up from a different disk, start up in safe mode, use macOS Recovery, and more. Learn more about these options, including macOS Recovery.
On an Intel-based Mac
To use any of these key combinations, press and hold the keys immediately after pressing the power button to turn on your Mac, or after your Mac begins to restart. Keep holding until the described behavior occurs.
- Command (⌘)-R: Start up from the built-in macOS Recovery system. Or use Option-Command-R or Shift-Option-Command-R to start up from macOS Recovery over the internet. macOS Recovery installs different versions of macOS, depending on the key combination you use. If your Mac is using a firmware password, you're prompted to enter the password.
- Option (⌥) or Alt: Start up to Startup Manager, which allows you to choose other available startup disks or volumes. If your Mac is using a firmware password, you're prompted to enter the password.
- Option-Command-P-R:Reset NVRAM or PRAM. If your Mac is using a firmware password, it ignores this key combination or starts up from macOS Recovery.
- Shift (⇧): Start up in safe mode. Disabled when using a firmware password.
- D: Start up to the Apple Diagnostics utility. Or use Option-Dto start up to this utility over the internet. Disabled when using a firmware password.
- N: Start up from a NetBoot server, if your Mac supports network startup volumes. To use the default boot image on the server, press and hold Option-N instead. Disabled when using a firmware password.
- Command-S: Start up in single-user mode. Disabled in macOS Mojave or later, or when using a firmware password.
- T: Start up in target disk mode. Disabled when using a firmware password.
- Command-V: Start up in verbose mode. Disabled when using a firmware password.
- Eject (⏏) or F12 or mouse button or trackpad button: Eject removable media, such as an optical disc. Disabled when using a firmware password.
If a key combination doesn't work at startup, one of these solutions might help:
- Press and hold all keys in the combination together, not one at a time.
- Shut down your Mac. Then press the power button to turn on your Mac. Then press and hold the keys as your Mac starts up. You might need to wait a few seconds before pressing the keys, to give your Mac more time to recognize the keyboard as it starts up. Some keyboards have a light that flashes briefly at startup, indicating that the keyboard is recognized and ready for use.
- If you're using a wireless keyboard, plug it into your Mac, if possible. Or use your built-in keyboard or a wired keyboard. If you're using a keyboard made for a PC, such as a keyboard with a Windows logo, try a keyboard made for Mac.
- If you're using Boot Camp to start up from Microsoft Windows, set Startup Disk preferences to start up from macOS instead. Then shut down or restart and try again.
Boot Usb Macos High Sierra
With a bootable Ubuntu USB stick, you can:
- Install or upgrade Ubuntu, even on a Mac
- Test out the Ubuntu desktop experience without touching your PC configuration
- Boot into Ubuntu on a borrowed machine or from an internet cafe
- Use tools installed by default on the USB stick to repair or fix a broken configuration
Creating a bootable USB stick is very simple, especially if you’re going to use the USB stick with a generic Windows or Linux PC. We’re going to cover the process in the next few steps.
Boot Macos From Usb Drive On Pc
Apple hardware considerations
There are a few additional considerations when booting the USB stick on Apple hardware. This is because Apple’s ‘Startup Manager’, summoned by holding the Option/alt (⌥) key when booting, won’t detect the USB stick without a specific partition table and layout. We’ll cover this in a later step.